When comparing FlatRedBall vs Melharfi, the Slant community recommends FlatRedBall for most people. In the question“What are the best 2D game engines?”FlatRedBall is ranked 47th while Melharfi is ranked 97th. The most important reason people chose FlatRedBall is:

Just check the commit frequency on github :)
https://github.com/vchelaru/FlatRedBall/commits/master
Plus Victor takes community input seriously and is known to shift around priorities based on the pressing needs of the community

Pros

Pro

Continually improving and open source

Plus Victor takes community input seriously and is known to shift around priorities based on the pressing needs of the community

Pro

Very easy to use

Simplifies routine tasks such as adding entities and files to the game, or tuning parameters, via the FRB Editor called Glue

Pro

Great community

Very active chat on gitter: https://gitter.im/vchelaru/FlatRedBallVictor (the creator of the engine) is available throughout the day to answer questions and solve any problems that may arise, along with the rest of the community members who are ready to assist in any way they can.

Pro

Extensive documentation

http://flatredball.com/documentation/Very good documentation not only regarding the API details, but also lots of tutorials covering different aspects of using FRB, either on the code-side or on using any of its tools.